1. Field of Invention
The invention relates to an inkjet printer that performs printing by ejecting ink onto a recording medium, and a method of controlling the inkjet printer.
2. Description of Related Art
For example, in FIG. 5 of Japanese Laid-Open Patent Publication No. 10-286974, which corresponds to FIG. 5 of U.S. Pat. No. 6,193,354, an inkjet printer is disclosed that includes an inkjet print head having nozzles that eject ink therefrom and an ink chamber that stores ink therein and is disposed on an opposite side of the nozzles so as to communicate with the nozzles, a cap that hermetically covers the nozzles of the print head, and a suction pump that is connected to the cap and sucks ink from the nozzles. In the ink-jet printer, with the nozzles covered by the cap, the suction pump is driven to apply negative pressure inside the cap. Therefore, air bubbles in the ink chamber may be removed together with ink by suction.
In the inkjet printer disclosed in FIG. 5 of Japanese Laid-Open Patent Publication No. 10-286974, which corresponds to FIG. 5 of U.S. Pat. No. 6,193,354, when suction with the suction pump is temporarily stopped, air bubbles, which have been suctioned into the cap, may possibly flow back to the inkjet print head immediately upon stopping the suction. In this case, even when the cap is removed from the inkjet print head after the suction, air bubbles may remain inside the inkjet print head and, in addition to air bubbles, dust and other foreign materials may flow back into the print head, resulting in ink ejection failures.
To solve the above-described problem, Japanese Laid-Open Patent Publication No. 10-286974, which corresponds to U.S. Pat. No. 6,193,354, discloses an inkjet printer including a mechanism that moves an ink tank up and down. The ink tank is maintained at a position where a level or surface of ink in the ink tank is above a nozzle surface of the print head, at least until the cap is separated from the print head after the end of the suction. Thus, air bubbles suctioned into the cap are prevented from flowing back into the print head.